The present invention relates to the management of diagnosis and treatment of infections prior to or in the absence of culturing the pathogen prior to commencing treatment.
Epidemiology is the branch of medicine that deals with the study of the causes, incidence, distribution, and control of disease in populations or the sum of factors controlling the presence or absence of a disease or pathogen. “Epidemiology” and forms thereof will be used herein in the broadest sense of all pathogenic, personal, and demographic factors that may be tracked according to the dictates of the present invention.
Symptomatic urinary tract infections (UTIs) are among the most common bacterial infections accounting for more than 7 million outpatient visits to physicians' offices and well over one million hospital admissions in the United States annually. In ambulatory patients alone, the national health care cost of uncomplicated lower UTIs is estimated to approach $1 billion. At a time when controlling spiraling health care costs is a national priority, improvements in the management of UTI is imperative.
Currently, when a patient pays an office visit to the doctor complaining of the symptoms of UTI, a presumptive diagnosis is made by examining the urine microscopically for microorganisms or by performing an indirect dipstick test that measures a microbial metabolite. Although these tests may reveal the presence of a microbial infection, they do not identify the type of bacterium present or indicate the drug sensitivity of the bacterium. Moreover, a urine culture is not typically performed if the patient appears to have an uncomplicated UTI; rather, a short course of empirical antimicrobial therapy is given. No follow-up visit or bacterial culture after therapy is necessary unless symptoms persist or recur. If any clinical features or other factors suggest a complicated infection, a bacterial culture is indicated and should be performed before therapy is started. Mitigating factors that would necessitate a culture include diabetes, symptoms for greater than seven days, recent UTI or antimicrobial use, use of a diaphragm, age less than thirteen or greater than sixty-five, and pregnancy.
In principle, the most appropriate antimicrobial to treat an infection could be determined by a clinical microbiology laboratory. That is, the infectious microorganism may be cultured, identified, and tested for drug sensitivity. In practice, this is rarely done because of the expense and because the demand for relief from the symptoms of UTI is too urgent to wait for results of such prolonged testing. As a result of the urgency for prompt treatment, antibiotics are generally prescribed empirically and with variable success.
This empirical method of treating patients without cultures or documentation has significant potential for complications and needless treatment of patients who do not have infections. Approximately ninety-five percent of patients with UTI have no serious risk of complications and empirical treatment is sufficient; however, about five percent have significant risk for complications which can be costly to treat and which can even be life threatening. For instance, if a patient is treated with empirically prescribed antimicrobials for a presumptive infection when in fact she has another more serious condition such as bladder cancer (which often has the same symptoms as UTI), obvious adverse results can ensue from a delay in diagnosis. However, the alternative of requiring repeated physician visits and cultures of all women who present with the symptoms of UTI is clearly inconvenient to the patient and physician and is unnecessarily expensive in the majority of cases. Therefore, there is an acute need for a method of treating routine UTI in an appropriate patient population that conserves health care resources while providing proper treatment to patients with more complicated conditions.
The diagnosis of UTI is complicated by the fact that there is a 48 to 72 hour lead time to obtain information from a urine culture on the type of pathogen and its antimicrobial susceptibility profile. The uncertainty about the proper course of treatment during this period can be reduced if comprehensive up-to-date data are available for the type of patient, regional location of the patient, and the timing of the infection.
Another aspect of increasing concern in UTI management is the growing microbial resistance to existing antibiotics. While there are other infectious diseases such as tuberculosis for which resistance is a serious problem, UTI is unique because of the large number of individuals affected and the difficulty of tracking resistance since cultures are generally not performed under the current treatment scheme. Since patients are generally treated on an outpatient basis, non-responsiveness to drug therapy could be due to drug resistance or to other factors such as non-compliance or misdiagnosis. Furthermore, drug resistant microbial strains can arise and spread very rapidly, but they are often localized within narrow geographical areas of socio-economic groups. Thus, even if there were more historical information available it may have little relevance to the current context due to rapid changes in drug resistance. Thus, drug resistance in any disease must be taken very seriously, but it cannot be monitored without a mechanism of collecting information, e.g., urine cultures.
UTIs are complicated diseases to diagnose and treat because the pathogens involved in causing similar symptoms may vary widely based on region, type of patient, and time. Put another way, UTIs are a heterogeneous disease. The heterogeneous nature arises from two main characteristics of UTIs: 1) there is an inherently variable nature of the pathogen, and 2) different patients may respond differently to the same pathogen and to the same therapeutic regimen. Resistance of the various UTI pathogens to antimicrobials may change due to any of the above, or other, specific factors. Therefore, there is an often unpredictable response of the pathogen to therapy. This is unlike a disease such as hypertension where cause and treatment are relatively predictable and static over time and geography. In the treatment of UTIs neither the cause nor the treatment is predictable unless a great deal of individual data are gathered and great deal is known about the most current state of UTI epidemiology in a particular locality. Current diagnostic practice, record keeping, and reporting of UTI epidemiology are limited relative to the scope of the changing nature of the disease. Further, only fragmented and dated information is gathered, and these data are not linked to relevant clinical data such as the type of patient, infection, or outcome of therapy. Thus, there is no current, comprehensive database, or records, system that would be considered adequate for providing predictable and efficacious treatment.
Additionally, there are other prevalent infections in humans that consume vast amounts of our health care resources besides UTIs. Similarly to UTI, several of these infections are characterized by multiple causative pathogens that cause the same or similar symptoms and the rapid development of drug resistance, which hamper effective diagnosis and antimicrobial therapy. These infections, which include, for example, throat infections and intestinal tract infections, also afflict large numbers of patients and cause large numbers of outpatient and hospital visits each year thereby taking an enormous toll on health care resources. Thus, cost effective and efficacious treatment of infections, including, but not limited to, urinary tract infections, throat infections, and intestinal tract infections, is of paramount importance in this era of spiraling health care costs.
As presented in the above-identified related application, a doctor-directed and controlled, patient processed, “Self-Start” treatment process utilizes a searchable medical record system that is created according to data entered by the patients or diagnostic laboratories or both. Using this medical record system, a medical practitioner is more accurately able to assess the type of bacterium, or pathogen, causing the infection in a previously undiagnosed, i.e., new, patient based on the collected data of previous patients. The practitioner can then further prescribe an empirically effective course of treatment for the infection in the absence of a diagnostic test performed on the new patient.
Specifically, the related application presented methods consist of: collecting information concerning persons previously presenting symptoms; organizing the collected patient information in an electronic medical record system; analyzing the organized information to identify one or more particular pathogens which caused the infection in one or more of the persons from whom the information was collected; for each pathogen identified, identifying personal and/or demographic information common to the persons who developed an infection from the particular pathogen; and identifying one or more antimicrobials which were effective or ineffective in treating the infections developed from the particular pathogen.
The related application also presented methods of establishing a searchable medical record system for assisting a medical practitioner in more accurately predicting a type of pathogen which has caused an infection in a previously undiagnosed human patient and prescribing an effective course of treatment for the infection prior to or in the absence of performing a diagnostic test on a sample from the human patient.
There is a great need in the treatment of UTIs and similar infections to provide timely information on a broad range of specific patient data and treatment efficacy that is readily available to the health care practitioner. Such information must be current and comprehensive to take into account the changing nature of UTI pathogens. Only an integrated system of information gathering, and knowledge retrieval from this information, on the pathogens and their treatment will yield viable results. This integrated system should be done as economically as possible.
While the previously presented systems of the related application, including the searchable medical record system as defined therein, provide a great help to the health care practitioner and to the public health system, all interaction with the data is either data entry initiated by a patient or a laboratory or a query issuance by the physician. Any self-organization or self-discovery processing of the database on its own is presented only as a passing aside. Rather than obtaining all knowledge by direct inquiries from the medical practitioner, it would further be desirable to apply database and knowledge and information discovery techniques to the collected data in an effort to improve public health.
In sum, there is a need for a medical records, or database, system that accurately collects relevant and current clinical data and analyzes the data to predict the causative pathogens and their rapidly changing drug sensitivity for heterogeneous diseases such as UTIs so as to provide effective therapy for infections while minimizing health care costs and the development of drug resistance.